Abstract
Investigations of light–matter interactions and motion in the microcosm have entered a new temporal regime, the regime of attosecond physics. It is a main 'spin-off' of strong field (i.e., intense laser) physics, in which nonperturbative effects are fundamental. Attosecond pulses open up new avenues for time-domain studies of multi-electron dynamics in atoms, molecules, plasmas, and solids on their natural, quantum mechanical time scale and at dimensions shorter than molecular and even atomic scales. These capabilities promise a revolution in our microscopic knowledge and understanding of matter.
The recent development of intense, phase-stabilized femtosecond (10−15 s) lasers has allowed unparalleled temporal control of electrons from ionizing atoms, permitting for the first time the generation and measurement of isolated light pulses as well as trains of pulses on the attosecond (1 as = 10−18 s) time scale, the natural time scale of the electron itself (e.g., the orbital period of an electron in the ground state of the H atom is 152 as). This development is facilitating (and even catalyzing) a new class of ultrashort time domain studies in photobiology, photochemistry, and photophysics.
These new coherent, sub-fs pulses carried at frequencies in the extreme ultraviolet and soft-x-ray spectral regions, along with their intense, synchronized near-infrared driver waveforms and novel metrology based on sub-fs control of electron–light interactions, are spawning the new science of attosecond physics, whose aims are to monitor, to visualize, and, ultimately, to control electrons on their own time and spatial scales, i.e., the attosecond time scale and the sub-nanometre (Ångstrom) spatial scale typical of atoms and molecules. Additional goals for experiment are to advance the enabling technologies for producing attosecond pulses at higher intensities and shorter durations. According to theoretical predictions, novel methods for intense attosecond pulse generation may in future involve using overdense plasmas.
Electronic processes on sub-atomic spatio-temporal scales are the basis of chemical physics, atomic, molecular, and optical physics, materials science, and even some life science processes. Research in these areas using the new attosecond tools will advance together with the ability to control electrons themselves. Indeed, we expect that developments will advance in a way that is similar to advances that have occurred on the femtosecond time scale, in which much previous experimental and theoretical work on the interaction of coherent light sources has led to the development of means for 'coherent control' of nuclear motion in molecules.
This focus issue of New Journal of Physics is centered on experimental and theoretical advances in the development of new methodologies and tools for electron control on the attosecond time scale. Topics such as the efficient generation of harmonics; the generation of attosecond pulses, including those having only a few cycles and those produced from overdense plasmas; the description of various nonlinear, nonperturbative laser–matter interactions, including many-electron effects and few-cycle pulse effects; the analysis of ultrashort propagation effects in atomic and molecular media; and the development of inversion methods for electron tomography, as well as many other topics, are addressed in the current focus issue dedicated to the new field of 'Attosecond Physics'.
Focus on Attosecond Physics Contents
Observing the attosecond dynamics of nuclear wavepackets in molecules by using high harmonic generation in mixed gases Tsuneto Kanai, Eiji J Takahashi, Yasuo Nabekawa and Katsumi Midorikawa
Core-polarization effects in molecular high harmonic generation G Jordan and A Scrinzi
Interferometric autocorrelation of an attosecond pulse train calculated using feasible formulae Y Nabekawa and K Midorikawa
Attosecond pulse generation from aligned molecules—dynamics and propagation in H2+ E Lorin, S Chelkowski and A D Bandrauk
Broadband generation in a Raman crystal driven by a pair of time-delayed linearly chirped pulses Miaochan Zhi and Alexei V Sokolov
Ultrafast nanoplasmonics under coherent control Mark I Stockman
Attosecond pulse carrier-envelope phase effects on ionized electron momentum and energy distributions: roles of frequency, intensity and an additional IR pulse Liang-You Peng, Evgeny A Pronin and Anthony F Starace
Angular encoding in attosecond recollision Markus Kitzler, Xinhua Xie, Stefan Roither, Armin Scrinzi and Andrius Baltuska
Macroscopic effects in attosecond pulse generation T Ruchon, C P Hauri, K Varjú, E Mansten, M Swoboda, R López-Martens and A L'Huillier
Monitoring long-term evolution of molecular vibrational wave packet using high-order harmonic generation M Yu Emelin, M Yu Ryabikin and A M Sergeev
Intense single attosecond pulses from surface harmonics using the polarization gating technique S G Rykovanov, M Geissler, J Meyer-ter-Vehn and G D Tsakiris
Imaging of carrier-envelope phase effects in above-threshold ionization with intense few-cycle laser fields M F Kling, J Rauschenberger, A J Verhoef, E Hasović, T Uphues, D B Milošević, H G Muller and M J J Vrakking
Self-compression of optical laser pulses by filamentation A Mysyrowicz, A Couairon and U Keller
Towards efficient generation of attosecond pulses from overdense plasma targets N M Naumova, C P Hauri, J A Nees, I V Sokolov, R Lopez-Martens and G A Mourou
Quantum-path control in high-order harmonic generation at high photon energies Xiaoshi Zhang, Amy L Lytle, Oren Cohen, Margaret M Murnane and Henry C Kapteyn
Time-resolved mapping of correlated electron emission from helium atom in an intense laser pulse C Ruiz and A Becker
Pump and probe ultrafast electron dynamics in LiH: a computational study M Nest, F Remacle and R D Levine
Exploring intense attosecond pulses D Charalambidis, P Tzallas, E P Benis, E Skantzakis, G Maravelias, L A A Nikolopoulos, A Peralta Conde and G D Tsakiris
Attosecond timescale analysis of the dynamics of two-photon double ionization of helium Emmanuel Foumouo, Philippe Antoine, Henri Bachau and Bernard Piraux
Generation of tunable isolated attosecond pulses in multi-jet systems V Tosa, V S Yakovlev and F Krausz
Electron wavepacket control with elliptically polarized laser light in high harmonic generation from aligned molecules Y Mairesse, N Dudovich, J Levesque, M Yu Ivanov, P B Corkum and D M Villeneuve
Tracing non-equilibrium plasma dynamics on the attosecond timescale in small clusters Ulf Saalmann, Ionut Georgescu and Jan M Rost
Ionization in attosecond pulses: creating atoms without nuclei? John S Briggs and Darko Dimitrovski
Angular distributions in double ionization of helium under XUV sub-femtosecond radiation P Lambropoulos and L A A Nikolopoulos
Potential for ultrafast dynamic chemical imaging with few-cycle infrared lasers Toru Morishita, Anh-Thu Le, Zhangjin Chen and C D Lin
Attosecond electron thermalization in laser-induced nonsequential multiple ionization: hard versus glancing collisions X Liu, C Figueira de Morisson Faria and W Becker
Ion-charge-state chronoscopy of cascaded atomic Auger decay Th Uphues, M Schultze, M F Kling, M Uiberacker, S Hendel, U Heinzmann, N M Kabachnik and M Drescher
Measurement of electronic structure from high harmonic generation in non-adiabatically aligned polyatomic molecules N Kajumba, R Torres, Jonathan G Underwood, J S Robinson, S Baker, J W G Tisch, R de Nalda, W A Bryan, R Velotta, C Altucci, I Procino, I C E Turcu and J P Marangos
Wavelength dependence of sub-laser-cycle few-electron dynamics in strong-field multiple ionization O Herrwerth, A Rudenko, M Kremer, V L B de Jesus, B Fischer, G Gademann, K Simeonidis, A Achtelik, Th Ergler, B Feuerstein, C D Schröter, R Moshammer and J Ullrich
Attosecond metrology in the few-optical-cycle regime G Sansone, E Benedetti, C Vozzi, S Stagira and M Nisoli
Attosecond x-ray pulses produced by ultra short transverse slicing via laser electron beam interaction A A Zholents and M S Zolotorev